SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eaadc598425d706999ff9f74eb9e73870c46e541e6a2c2279b240c6c15be7a7' 
  AND token = 'ZgQEhTitFVmckGD6zhKJqDHnjhy5LXbyMgIF+BwrKkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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