SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9757aef3e1eb18961def8b6cc97069fd7883a7fbb4490a979279e1ee9458bd06' 
  AND token = 'U2qU6dz+Axdl2D/zxII3/CbVglFLQ8riL/0wVbJjhXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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