SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d8e43a6abf78d0d17632cc958797905bdaeb8fef53db44a885abb8e64764332' 
  AND token = 'IyonMeg4fr1zkCMDIjk6YUAXtgLPa0mgoq7VOOVEfS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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