SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2d1c029943be0c0ff540eed2197b777c03cc4a9381507ad66fde43063c525e9' 
  AND token = 'IfcU4SlID49UHgikxk+/s0y9N4NAbIV4zhAo2i6ttjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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