SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c189de420ade773764ba65399098ab22fa3be57903205f5610f7ecaa4d23862' 
  AND token = '9GJnARD5U/2MuV30U9snxYWujJK9AK5qHji3Fjfp+mU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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