SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c9f4529dc95b403324934f4677a10a05803d5d26778b07f43a320eb53185ea7' 
  AND token = 'QZox9XPaIZIGNWr9gh83zdHW81oiuzV2UbeY+Cksjww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}