SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82dab8f36b153081f2ad593ad5a51319a613c742211e50d66e03873698f8ff68' 
  AND token = 'IK0AiBJx+bz1IRukpkYJ6TN/VHZoncWJhyTrAhQ9Qd0=' 
  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"
    }
  }
}