SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63e35e2194538939f2cec2bea581b698733ca7fe719ea14dc8d5818c27d1be56' 
  AND token = 'hiKdSu+pgBTV8DhaNlPIGlJr1RwXaqT35BENPDuyK54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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