SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1e8af6e1df1fa4f76da5a076d259c645278afffa0b9931869f911046827a9eb' 
  AND token = 'jF/rcooDCmUQ3EGkl8NOTd1BtC+efCZgtIPHvQBuscE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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