SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05be1d6acfe3a24a10c751f2c51016e7a08bca9524d78034dc393286d3006e5b' 
  AND token = 'YwwBlq3QuauJ3FpRU5RmtGezauxOFFvVIJvcpFvgqqQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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