SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7465d4340623f5d12c2dfbf2d7cb09d1e1527b12fb250443c7cc5e77bc8a590c' 
  AND token = 'XKJloAlAvIwPyxsaSsUakBqMrfzydpYTgt1t2Oty/xc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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