SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4746657de825c222337b2d2e291c86b2d989c6026db349f1ca49e52e5faf3646' 
  AND token = 'pJA0k2pyDPH69cufYNoMemAmhqnXPazCYAJc/eHI5sc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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