SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '872fbe82afb05b34a48faf18cb12e9551848794fd6ef7b7d3a0097666aadb6f8' 
  AND token = 'VujauEMLUXxNxSwRR3z1qL3FKwUOkhI27sTDkLVj4+U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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