SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2140130051235f66d2d2a66297780e735e24364369bb7d1ee7040b9738a65177' 
  AND token = 'wi40NmzZlv4OiA/Ljucz7jkjv9wEb38Ds105lbD8muM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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