SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fe066d24c1bcb345c0d8b1f3f71c876ccf36f9203d53ac0be09ad02b2599d6c' 
  AND token = 'rrSSGHx8tlBwWpoWOZORhtrUKLUKs6ClBemp6QFd/pE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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