SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c13ad3e3e16b4b7bfb3b7cd193daacc523c809981324b2a65773ecd7193d53f' 
  AND token = 'uEgEcwNMiX4a0NNC/LWJKwb6vXUMB7oeeCgUUy8fN9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}