SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f09d39ae0dd0d71ee3dba0a5ba72e3b767f3d6720a942763ecc7785625b573d' 
  AND token = 'ZNyPLyUOg1tezd+qdbkCrJny75sJfzUdizKXdWBoIZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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