SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79156d94475e9e8b454bea67a83c786f63aa634ed5349c3755300a10b0d2f113' 
  AND token = 'ghAwMFZKZK2xOHZZSfEcL6MGel3HmQlJwEVuzIULzX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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