SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '387e83ea5711a41cf0cab4053a9c2376c14b0dd50837176f1a856e75b22baab5' 
  AND token = 'hutL/g+jnRUNhWQowaenP1CoBBspwufemAxNcSDp9nE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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