SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '606a9173710d262abaac59498ab9f0e91b2da0201e8fc3ea73a2aeab2fcde01a' 
  AND token = 'iLYOT5uEGLc+glOaS5T5xuv8lCpfQhCq4t2PqVaAJFE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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