SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0253c39549482cc8189448d929ae9696436ab9b89f203f9a4d53eb677110c63' 
  AND token = 'qgzIDBoH8lUJM/DKSjDPe57xsjwIvZeDDwoO8eOIjF8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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