SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b6b02be00e9aa52e2f24c5cec363fd560b3ae440ec29d51a4414baf2b591e0a6' 
  AND token = 'BPEJffFxnfsAgwo1x+AvupO/5vQGhiwhY7OHP6myffI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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