SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fd6725954f62c2da0b68dd875d28a7270ea6a06a5e65d0e9d8813c918e1d477' 
  AND token = 'I0layJ7lD2qllT19jVRuBk8/A73Rnwm6qLAUBUi7a38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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