SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b8481904c59abe5171f919d5e2dd84a645ff887f1da3912412a9cc53593f101' 
  AND token = 'o6oOGobk1YBJyn2KmJX69QJQ9aOGabVP0bTPGx+GpXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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