SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f84393541f7af4fad9ff36946bf12e31df252d5e1e30af942ae567faffbc20e7' 
  AND token = '9LiTJRcT89yCZpufosWajHx8c5vF1qmwX3RPNuI/ZEY=' 
  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"
    }
  }
}