SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd93ddd228addf8f05eba1b18f7cda08813766c9beca42dfee59c7ec15a1541b' 
  AND token = 'X9hgDhwQV8vVulQotGKYp0D7D5IKWnf/Sc+n77nOz4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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