SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71aeab29ea62abb2b260dfce933bbbe419a7865454608f84879b578c8a5cf4eb' 
  AND token = 'BUzzl9kdcOPKEeGCC2qu2pJHF7rNpHbh5hqJMHTE3es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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