SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e120bc42e8e647d845125f5af9f989ff5139abccdd753cd9c27886101ce38914' 
  AND token = 'UHJmalw2KDFSaIdeEuc/LyUVDfcT5hJJoWKazVaBLFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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