SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9dd486c63f827884e558fffd9cb9bcd710c4d1df9cdc513d358228f9454e609b' 
  AND token = 'ZrjhAOEh/LaSzvLkjc6zoKyOZaBPB0Fg4lAVlQs5CjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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