SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '548117f74faa510431af57fda74cc5b7d28bbc7ff15adba9e614da71bbe5e2c4' 
  AND token = 'UBzD/EIFxlKIbbVl9v3cbt0KQY0XqtTUeUzcztfl6yI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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