SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29738d2ca8b3e5713bc23d18d6281b133321c3b7f778be7860cd4390f3b6d5b7' 
  AND token = 'NhepuPcLyw+a6zHkmZbWKEnCb7Tq4w6P720yTId2kso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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