SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e105fbcf50df44b2a22421e748725a9553db2aa26afeb22caa4c79499d1063' 
  AND token = 'BTAP8fgc9KnM5Rir7fVpMMkmK1jrpGoCFlYTFy4f6tM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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