SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5edbecb5ab0ed093f1524e2bbe612b8a154ec0002342c1910b04ffa3ffd4bc03' 
  AND token = 'ONkCauv3bB4DUeIzuXtPQHBr1oDPuc9ERCiV3itfqE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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