SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b27b939a78c91f5a902ea8d238b37643003ad844b2477516579701f42b64b9f7' 
  AND token = 'ALAN+QEq0pt3cfXc2FULvq4jcvViWTf3G6KknP5PHec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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