SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82a2066ca32760612ed7eb089740ba9657fc14fcb9e8391474e5f0404ea39029' 
  AND token = 'pDUUi4uuVo+IJl+KHoO7wNfzdlhZ/huu+Vn3q9NrwAk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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