SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '294e9e7ade70eec1a47c7878590ce190d7ff272b0cbfb8ed76176f82bb911aa4' 
  AND token = 'b+74+87R6NoKA/lQmBxy1Ep2CsbMFnCiqpeR5QxWoSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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