SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50d59c18405e4946838fe539fd1a7bb7569d2cb02969f77baf49b966e0202efb' 
  AND token = 'h6FJQvLZTLuX0d3rynespd6Hz72xtCknNWrwD9HqXfo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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