SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3025e2405f18325922584635c0fce4ed7d6cccba3e1e9984862bf753c698c22' 
  AND token = 'IxlJd99JoZju8S73u/ulXTiQWpreQSFdDyIYwFbxRKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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