SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c82bdb120dea83038d4bd93927898a7e29ef0a8d63e1c46323f7508e3eb5de' 
  AND token = 'NZu56MugZtxCPTryPwN+vIr6cdQTlCPN8Fl1RPUlaZg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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