SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41cfd69ce4b7c5ac560a0c5ec27d546fd743fa85849eaa6c2edcc4b70bc1cfa0' 
  AND token = '0ZkhwzUNm7+qfSMzVUnHzN8fsK0kk6LWUp5K1GwwVRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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