SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0690f22bdaf81c7c974201af2903a2b5e9aaba32cfaa31eb712aeaacda80599' 
  AND token = 'AN0KEFd4Sjj8pNyOiMTRhmczlsoobfEsTPrZd62/td8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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