SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe49e34ad4d019db423c167320bd44d2d47ef2461ea0a7eb0d6456d22304939e' 
  AND token = 't8PMSDmfRm87ERJ8BLjnp7px1LaoimlKoyv6Us4mwTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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