SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5bf38c17f18d3653be9b14d7ac8c9db1db2c33385fbebff048909a096aa0eef3' 
  AND token = 'BXuQM0Ui38K1753/sxHIIntFANenpUX8iOcTcweYpRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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