SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c9d490c588d9f0da816d356f599402db1fcfc8de8a28e315748e519fd3c07a82' 
  AND token = 'hA7u3SGaDEBhsYr/h7C234gXVEPqaGSreWoLSRduDLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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