SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c665c73f3df55d83654e9236f175485970a7f89c9417f0de690df0489c1477e7' 
  AND token = 'i0+5nnWMq82vO9zJhtJZvgnVKuZ1MkHdvRORyiPRe0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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