SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a2145741e440375a727e8b6027c33e5c2916cb3042c4c4a1ad7b4bbc7cefb1c' 
  AND token = 'KGundwPLusAuXCE3pC7INpAAqxl4xndKKbxrKf0R7RM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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