SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '14f1e1fbe794bd608735e8ea05c14ce7d475342ddf4562b13a06457f788c61b1' 
  AND token = 'YToT6QraeXCHAsNs6Ano+KUsfZCZnzejlnixJxF53rM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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