SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '760ec71accca3e3f0712f080eff98434cb245611e4fcc5165d99d7ab5d51b846' 
  AND token = 'lf2TssNgppP2tarxkQkRWpJRTiD/U9AlqBtMqyyAyEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00162

JSON explain

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