SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '951c96c80d88fbb34e3ba4b1271cbd503083f15decef5211375064ae235f2d24' 
  AND token = '78DKDHnUU7AmJAqFNYzi4hpCWYKR1FGnwt5vNvg9I+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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