SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824f4e839d71aa53515cd98229dffc1e7d2ce6967f044cb940c7fb686f9b1142' 
  AND token = 'iqZ54YOZt+YhO6+hy4XEnFQSBlpXkd0evvpDSEQpxSc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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