SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7fe4d24f5622e86d2a45376c82243decfa7fd56db9778ceb52baf60848318b61' 
  AND token = 'd2jSk1HzR9ZDnjxNVqDaF6ZdbJBfqbRbgZcI3FjXEU4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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