SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '381778b006348fa1b69509267c6d6f7eea64dbc1894dda49a87176fe5a059d27' 
  AND token = 'kLt6b8rETfX68R/YSLiEKgaQPJyEn9oEYyvHLB0rinc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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