SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '93e96f1f406af9cdd892624a11e163635afa4ae42c737885fcbc109f9a3fc7f1' 
  AND token = 'CD55ecRiOXx1mVhpf5NrKgvg44WAJqibiNMuokJV3ts=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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