SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a3eb2c4cd9f5f13e6d77271e13a60197dce0e764d50360091721f06078c5d98c' 
  AND token = 'U1hE9ahq1tHM0OwcxmaHYWMuuXTLvgJUf9OgDmQf0c0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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