SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f34a3ddc1f135c09a06c01da6c1379bd0b171740310d9c394eb159a379732b9' 
  AND token = 'Y8w6gqjWo+FhG7c7yd6Bzm5HwcBg64S7Uhr3/v24EcU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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