SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd1241dc07732dfb6841de4d76be1b55fa9622a655798d8a05698af2a1c83a55' 
  AND token = 'jGuSflZ7fwY9epImWi8QXdK7q4owcfqGCO67CX4xhJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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