SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '238e148fceed5e647f721ade2baa8e577ec96c0ac5ef105257de9ee29da6e967' 
  AND token = 'C3m3yEgh4o5A+CDJzpxK6SI4AKBYrFdxDaLgZegWz/g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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