SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f27e86d458942827883f333fe746773c276320378d6c8076ca82283da0f928b6' 
  AND token = '5eT1w/qmrJLAoJNid2UAVMyjWpZTmI3a8C5VNLAvPws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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