SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '81e8a5a34d3f7a8b759b38e918c56958c5a94b98c25da7a6d82d8f5fef93d333' 
  AND token = 'CfX3R3qz/UGAwPWWu19o+BPhMYkei4SjurtLG24enVI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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