SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ca1df5addd7fef9e09687ce1c772e4338d9f151563b493071d9a6d732c56bd7' 
  AND token = 'Dwt/zirtVoVGA9IfNAZioceWcqs1Wyj2XotiAkYUwQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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