SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a551f9cf32ab6f589420efca02ee5f69dee94565753a81a0d2babb1ef7c5d6e' 
  AND token = 'EawmagM7GKJ32yPDAEOlep5eaUqYve7w/nJa38HpVpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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