SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '205da62ee205aa7a2223a6de6e10260af33d48afcbc59a8c58e8afaab7b28adb' 
  AND token = '0LJ4x3VY98WRutQhr2ZiWrDCLvRMWicl+2XBijRBoXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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