SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a882d5be8c52c545960fc88668b40ef43cbd22d92a0d6c1db80a528f5e93c768' 
  AND token = 'oERienmarNZxB+MaL9e/uElt22EcdfSL8wSDUOy8hZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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