SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbcaa2f5e5c8c24ec695e9585c5af467bc9bf1c4114d92eca6fe41a75e7673b6' 
  AND token = 'mD0fwv23FamiMTEuqV4mj3Z7e7acJMsRdcirHO6ZM4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}