SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c42ea03941cd422b049bca12edad0577ec9d1c59044b25da19bebbcaffb2636b' 
  AND token = 'XJFODCv8pkhep7OWbIKF8h4GWEbolrWR1fIL8u1TTHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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