SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d9bc4ee05dcd1507825a247c1e2202f0927d5ba11a3a0944f7541f4b49a9256' 
  AND token = 'uSiCZI9r0o7gaWLZT0qUJI/l8cbW8Unror3oS/1txJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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