SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a634dc6fc75c6280d4a7a2bd671098aefdd815a0f2c7945a8582d4dec432fe15' 
  AND token = 'dnoTRpE1Vfc1hD4cX/hb/OZDvcw4a6mFsjrp8AN53Zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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