SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '602b8e2a9ec55340bfcfd1b988d2c3d8fc16666614c8942ee0562fdebb22bcf1' 
  AND token = 'mf7g2cV38yTNvyI16PZ4DiazwECwNyKnGOTxlEay9tE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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