SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '331e74844e11a52206bf3a82c798017c66ce093a15774778de201db520a38e76' 
  AND token = 'ry09JGHN/PoCgA7oy+EdqmFPJTEkzaSC4On7qiV5ink=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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