SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '430ed9d5b90693152980612f3313f3ef38aa642d62df43e962750c75800acbb7' 
  AND token = 'FbQz6w4XCd8anJs6D5xlK85XTomGuBw4mkl4M+34C1A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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